Lexicon of Elastomer Technology

Additives that protect elastomers from UV, ozone, and thermal degradation. Especially important for EPDM, CR, and Silicone in outdoor use.

Mixture of different polymers. Common blends: PVC/NBR, TPE/PP – to combine elasticity, temperature resistance, and processability.

Used to ensure adhesion between NBR, FKM, EPDM and metal or plastic in multi-material parts.

A mix of base rubber, fillers, curing agents, and additives. Each material (NBR, HNBR, FKM, etc.) has tai-lored compounds for specific uses.

Used to produce foam rubber, EPDM, FKM, Silicone, or TPE components, especially seals and gaskets.eee/c

Measurement of permanent deformation after compression. Critical for long-lasting sealing materials like foam rubber, FKM, and Silicone.

Used with foam rubber, EPDM, PVC to install seals or insulating profiles.

Chemical (for EPDM, FKM, NBR) or physical (for TPE). Determines final mechanical properties.

Chemical process (e.g., vulcanization) that gives rubber its elastic properties. TPE achieves elasticity through physical properties and does not require curing.

Typical values:
PTFE: very high (~2.2g/cm³)
Foam rubber: very low (due to cellular structure)
TPE, NBR, EPDM: around 1.1–1.3g/cm³

Elastomers such as CR, HNBR, and TPE perform well under vibration and impact—used in mounts or shock-absorbing components.

Excellent weather, ozone, and steam resistance. Not oil-resistant—NBR, HNBR, or FKM are preferred for oil applications.

Examples: carbon black increases strength (common in NBR, CR); chalk reduces cost (e.g., in basic PVC compounds).

Resistance to repeated bending and flexing. Silicone, EPDM, and TPE perform well in this area—important for dynamic seals and flexible connectors.

Typical ranges:
TPE: 30–90 Shore A
Foam rubber: very soft (~10–30 Shore 00)
PTFE: hard (Shore D)
FKM, HNBR, CR: medium to high hardness (60–90 Shore A)

Efficient method for complex parts made from TPE, FKM, Silicone, CR, etc. Fast, repeatable, automated.

Ideal for TPE, Silicone, PVC, FKM parts. Ensures high precision and fast cycle times.

Main component of natural rubber (NR). Also found in synthetic IR rubber, less common in technical seal-ing.

Measures impact resilience – less common for rubber, more relevant for TPE or PVC under sudden loads.

German term for elastomers. Covers materials like NBR, EPDM, Silicone, CR, FKM, HNBR, etc.

Rubber compounds (EPDM, NBR) are processed in internal mixers. TPE and PVC are processed thermo-plastically (extrusion, injection).

PTFE: very stiff
Silicone, foam rubber: very elastic
FKM, HNBR: balanced for technical use

Excellent elasticity but poor oil and ozone resistance. Often replaced by EPDM, Silicone, or FKM in de-manding environments.

Great oil resistance, moderate weather resistance. HNBR offers better heat stability; FKM offers superior chemical resistance.

Unwanted excessive vulcanization. A concern with EPDM, NBR – not applicable to TPE, which does not cure chemically.

TPE is ideal for 2K molding (e.g., soft-touch).
Can be combined with metal, PP, PA, etc.

High: EPDM, FKM, Silicone, CR
Low: NBR, foam rubber (unless stabilized)

Alternative to sulfur curing – used for FKM, EPDM, Silicone. Enhances heat resistance and lowers emis-sions.

Used for foam rubber, EPDM, FKM, Silicone parts.
TPE is generally injection molded.

From compound mixing to final product – varies by application (e.g., aerospace-grade FKM vs. basic foam rubber).

Uncured base elastomer. TPEs are already processable thermoplastics—no raw rubber phase.

Excellent in Silicone, TPE, natural rubber
Low in PTFE, which behaves more plastically.

Generic term for elastic polymers. Includes NBR, EPDM, FKM, Silicone, CR, HNBR, etc.

Used for NBR, HNBR, CR in vibration damping or engine mount components.

EPDM, FKM, and PTFE are highly stable. Natural rubber and soft TPE can degrade over time.

Examples:
TPE: wide range
PTFE: ~60 Shore D
FKM: 70–90 Shore A
Foam rubber: very soft (Shore 00)

Best materials: FKM, FFKM, PTFE
Poor resistance: EPDM, TPE, foam rubber (open cell types)

NBR swells in fuels, EPDM in oils.
PTFE, FKM, FFKM resist most aggressive media.

Strong: HNBR, FKM, NBR
Weak: Silicone, foam rubber

Top performers:
FFKM: up to 300°C
PTFE: up to 260°C
Silicone: up to 230°C
TPE, NBR: ~100–120°C max

Excellent: HNBR, FKM, TPE-V
Low: Foam rubber (open-cell structure)

Excellent: FFKM, FKM, Silicone
Moderate: TPE, NBR

High: EPDM, FKM, Silicone, PTFE
Low: NBR, PVC, TPE-S → needs stabilizers

Essential for classic rubbers, not needed for TPE, PVC.

Important for TPE, PVC (more plastic-like). Classic elastomers don’t have a clear yield point.